Magnetic sensing devices have many applications, including navigation, position sensing, current sensing, vehicle detection, and rotational displacement. There are many types of magnetic sensors, but essentially they all provide at least one output signal that represents the magnetic field sensed by the device. The Earth, magnets, and electrical currents can all generate magnetic fields. The sensor may be able to detect the presence, the strength, and/or the direction of the magnetic field. The strength of the magnetic field may be represented by a magnitude and a polarity (positive or negative). The direction of the magnetic field may be described by its angular position with respect to the sensor. One of the benefits of using magnetic sensors is that the output of the sensor is generated without the use of contacts. This is a benefit because over time contacts can degrade and cause system failures.
A Hall sensor is a type of magnetic sensor that uses the Hall Effect to detect a magnetic field. The Hall Effect occurs when a current-carrying conductor is placed into a magnetic field. A voltage is generated perpendicular to both the current and the field. The voltage is proportional to the strength of the magnetic field to which it is exposed. The current-carrying conductor is called a Hall element and it is typically composed of a semiconductor material.
Various semiconductor devices have been designed, fabricated and mass-produced utilizing the Hall Effect. For example, Hall Effect switches and the like commonly employ a silicon body through which a bias current is passed between two spaced apart contacts or terminals. Sensing terminals are positioned on opposite sides of the bias current path and exactly located from the two spaced apart bias current input terminals to detect a voltage potential in a direction perpendicular to the bias current path. Ideally, zero potential is developed between the sensing terminals in the absence of a magnetic field.
Hall offset variation generally reduce the performance of magnetic Hall Effect sensors (i.e., “Hall sensors”) by increasing the minimum detectable magnetic field. A need thus exists for a device, system and/or method for effectively reducing the offset variation of a Hall sensor from product to product, thereby increasing the signal-to-noise ratio resulting in increasingly sensitive Hall products and devices.